The present invention relates to rolling mills for producing metal shapes and in particular to a rolling mill using an industrial controller that automatically organizes the components of the rolling mill for the manufacture of a product based on the capabilities of the rolling mill components.
Rolling mills employ a set of movable rollers to shape metal billets into a variety of "shapes" such as angle, channel or rod of various diameters. A rolling mill is typically used as part of a rolling mill system, including for example, an upstream reheat furnace or continuous casting machine providing heated billets, and a downstream water bath or Stelmor conveyor cooling the rolled material.
A given rolling mill system is capable of producing a wide variety of shapes by a changing in the operational parameters of the system, including the roller dies, die separation, rolling speeds and temperatures. In a rolling mill system including multiple rolling mills, furnaces and cooling baths, the path through the machines may also be varied.
Reconfiguring a roller mill system is currently time consuming and expensive, and involves not only setting the operating parameters for each of the component pieces of equipment, but ensuring that there is consistency between those operating parameters. For example, the speed through the water bath normally must match the desired rolling speed through the rolling mill. This step of ensuring a matching of operating parameters between the component machines of the rolling mill system complicates the selection of optimal operating parameters and makes determining the trade-offs between the settings for different machines harder. This arises from the fact that although each machine may be modeled in a forward direction, that is, it may be determined how a change in rolling speed or die separation affects the billet temperature, the machines are not easily modeled in the reverse direction where there is no functional mapping. Thus, if a downstream water bath requires a different billet speed from a rolling mill, adjustment of the rolling mill presents a complex variety of alternatives.
For this reason, it is normally desired to minimize the changes in rolling mill setup, a desire that is at odds with economic demands to change the rolling mill setup frequently and quickly to respond to changing product demand. It would be beneficial to have a rolling mill system that could automatically and quickly organize itself to produce the desired product. It would further be desirable that this system accommodate a large variety of different types of rolling mill equipment.